Low temperature thinning of thick chemically vapor-deposited diamond films with a molten CeNi alloy

Thinning of chemically vapor-deposited diamond films has been achieved using molten rare earth alloys at substantially lower temperatures than those previously possible through the use of rare earth elements. A Ce-22%Ni eutectic alloy is shown to reduce the diamond etching temperature by more than 200°C below the pure rare earth metal's melting temperature with no noticeable deterioration in thermal conductivity. The molten alloys provide fast reaction kinetics at practical temperatures (less than 600°C) for industrial application. A large number of diamonds may be processed simultaneously in this manner without compromising the material properties of the diamond.